1. Field of the Invention
The present invention generally relates to a battery module. More specifically, the present invention relates to battery modules that are stacked on one another.
2. Background Information
Sometimes battery modules are arranged in a stack with end plates provided on both ends of the stack of the battery modules to form a battery module cluster or assembly. The end plates are usually fastened at each of the four corners with a fastener that includes a fastening bolt and a nut arrangement such that a uniform surface pressure is applied to the battery modules. An example of this type of arrangement is disclosed in Japanese Laid-Open Patent Publication No. 2007-66625.